Embryonic stem cell treatments are edging closer to mainstream medicine. An experimental treatment just approved for clinical trials may provide hope to the 10 to 15 million elderly patients in the United States who suffer from a common form of macular degeneration, which causes gradual blindness.

The biotech company behind the treatment, Advanced Cell Technology, Inc., previously won FDA approval to try an embryonic stem cell treatment on patients with a rare, juvenile form of macular degeneration. The new FDA-approved trial will use similar techniques, but targets a much broader patient base.

“ACT is now the first company to receive FDA clearance for two hESC (human embryonic stem cell) trials, and is now a true translational leader in the field of regenerative medicine,” said chief executive Gary Rabin. “It marks a major step forward, not just within the stem cell sector, but, potentially for modern healthcare techniques.” [AFP]

The treatment for “dry” age-related macular degeneration will initially be tested on 12 patients to determine safety and tolerability of the implanted cells.

“Dry AMD is the leading cause of blindness in individuals over the age of 55,” Dr. Robert Lanza, ACT’s chief scientific officer, said in a statement. “As the population ages, the incidence of AMD is expected to double over the next 20 years,” he added. [Reuters]

Patients suffering from “dry” macular degeneration slowly lose their sight, as the retinal pigment epithelial cells in the macula (the central part of the retina) die. The vision problems begin in the central area of vision, gradually worsening and spreading outward. There currently aren’t any effective treatments for the dry form of the disease, and vision degradation is permanent:

“Once you lose the RPE cells you no longer have a healthy environment and you start to lose photo receptors,” said Robert Lanza. [Bloomberg]

In the upcoming trial, the first patient will be injected with 50,000 lab-grown retinal pigment epithelial cells that have been derived from human embryonic stem cells; the treatment has been shown to improve vision in rats. If the treatment is deemed safe, further patients will be given injections, eventually increasing the dose if the injections don’t cause problems.